/Engine/Source/Runtime/Core/Public/Math/TransformNonVectorized.h
Set current transform and the relative to ParentTransform. Equates to This = This->GetRelativeTransform(Parent), but saves the intermediate TTransformstorage and copy.
void SetToRelativeTransform ( const [TTransform](API\Runtime\Core\Math\TTransform)< T > & ParentTransform )